証拠 shou ko evidence, proof
保険証 ho ken shou - insurance card [A]
Wait until someone uses the shredder at the office and then announce to everyone, 証拠隠滅
The shredder scene is most effective, however there are other possible applications. Take, for example, the taking out of trash, the tossing of logs on the fire, being asked, "Do you have any WHITE OUT?," and an open mouth ready to take a bite of food.